1. Field of the Invention
The invention relates generally to circuit breakers and, more particularly, to a seal apparatus that is employable in a circuit breaker application.
2. Description of the Related Art
Circuit breakers are generally well known and are used in numerous applications. For example, circuit breakers can be used to interrupt a circuit under one or more predetermined circumstances, and can be used for other purposes.
Certain types of circuit breakers are mounted in switchgear cabinets during ordinary usage. A typical switchgear cabinet may have a number of electrical conductors which terminate at stabs that are disposed within an interior region of the switchgear cabinet. A switchgear cabinet that is employed with draw-out circuit breaker equipment may also include a slidable cassette within which a circuit breaker is mounted and which enables the circuit breaker to be movably disposed on the switchgear cabinet. Specifically, such a circuit breaker is movable between a racked position wherein a number of finger clusters on the circuit breaker are physically and electrically connected with the stabs, and an unracked position wherein the finger clusters are physically and electrically disconnected from the stabs. While such draw-out switchgear cabinets and circuit breakers have been generally effective for their intended uses, they have not been without limitation.
As a general matter, the line stabs of a switchgear cabinet, i.e., those stabs that would be connected with an electrical utility or other power source, often can be considered to be “live”. In most situations, the racking and unracking of a circuit breaker in an OFF condition does not cause electrical arcing between the stabs and the finger clusters. Such electrical arcing can occur, however, in a situation where a fault exists within the circuit breaker, for example, or in other circumstances. Such arcing is undesirable because the explosive energy that is released can be dangerous to an operator and can be destructive of the switchgear equipment. Such an arc may occur during a racking procedure when the stabs and the finger clusters are sufficiently close to one another that an arc can be formed therebetween. During an unracking operation, an arc can occur when the stabs and the finger clusters are physically disconnected but remain sufficiently close that an arc occurs therebetween. Such an arc can remain between the stabs and the finger clusters until they are separated by a sufficient distance to extinguish the arc.
Such circuit breaker faults and other conditions are known to exist, and thus the potential for undesirable arcs within a switchgear cabinet remains. It thus would be desirable to provide an enhanced level of protection from arcing in draw-out circuit breaker equipment.